Roll lathe tailstock



Aug. 3, 1965 J. N. BINNs ROLL LATHE TAILSTOCK 6 Sheets-Sheet 1 Filed Jan. 31, 1962 INVENTOR JACK lV. BIN/V` BY ATTQRNEX 6 Sheets-Sheet 2 Filed Jan. 31, 1962 INVENTOR JACK N. 5IN/V5 BY Wm ATTORNEY Aug. 3, 1965 J. N. BINNS ROLL LATHE TAILSTOCK 6 Sheets-Sheet 3 Filed Jan. 3l, 1962 INVENTOR JACK M B//VNS BY MM a@ ATTORNE ,l lll 6 Sheets-Sheet 4 Aug. 3, 1965 .1. N. BINNS ROLL LATHE TAILSTOCK Filed Jan. 5l, 1962 INVENTOR.

6 Sheets-Sheet 5 Aug. 3, 1965 1. N. BINNS ROLL LATHE TAILsTocK Filed Jan. s1, 1952 JACK lV. B/NMS` ATTORNEY Tillllll.

Y IIITIIIILITI Aug- 3, 1965 J. N. BINNS 3,198,042

ROLL LATHE TAILSTOCK Filed Jan. 31, 1962 6 Sheets-Sheet 6 INVENTOR. JACK N. BIN/VS S\ BY ATTQRNEY United States Patent O 3,198,042 ROLL LATHE TALSTCK Jack N. Bilans, 4886 Oaklawn Drive, Cincinnati, Ohio Filed `lan. 31, 1962, Ser. No. 170,046 2@ Claims. (Cl. 552-31) This invention relates to improvements in tail stocks, and has particular reference to a structure for use in connection with heavy duty machine tools such as roll turning lathes or the like.

An object of the present invention is the provision oi' an improved tail stock structure which can be particularly eiliciently and effectively employed to support in a machine tool very large and heavy work pieces such as rolls for metal rolling mills.

These particular work pieces or rolls are necessarily formed from steel or corresponding material, frequently several feet in diameter and from six to eighteen or more feet in length, and often weigh in excess of a hundred thousand pounds. When such a work piece is to be held between centers for its rotation, if the head stock and its center are fixed and the tail stock center movable, even though intermediate steady rests are employed for partial weight support, a constant high clamping pressure must be exerted against the tail stock center to maintain itrand thus the work piece in proper position for accurate machining of the desired surface of revolution thereon.

High speed machining or metal removal, under most favorable conditions in a work piece of this size, results in heating of the work to an extent which affects its overall length, and for this reason a fixed and unvarying clamp positioning of the tail stock center in undesirable. Heretofore it 4has been desirable, if not imperative, that the position of a tail stock assembly be incrementally adjusted from time to time relative to the iixed head stock in an amount which would compensate for axial work piece expansion and contraction.

One of the objects of the present invention is to provide an improved tail stock assembly in which the position of the work piece engaging center will be automatically varied to compensate for any changes in axial length of work piece due to temperature changes or otherwise, without varying the holding restraint or pressure exerted against the work piece.

A further object is the provision of a structure employing a iirst work piece center clamping force which may be in the nature of a high pressure-position yieldable hydraulic operating mechanism-supplemented by a concurrently power actuated mechanism for automatically locking the center in all positions against a retractive axial movement from its then existing position, in the event of pressure drop, power failure, or shut down of the machine.

Another object of the invention is the provision in l connection with an axially movable hydraulic actuated tail stock center of a power operated sensitive mechanical safety follow-up mechanism continuously available and selectively etective to lock the center against accidental or unintentional retractive axial movement.

An additional object of the invention is the provision of a structure as aforesaid in which said mechanical mechanism may be alternatively utilized, when desired, for effecting axial adjustment or positioning of the tail stock center relative to the tail stock frame.

The objects of the invention also include the provision of a tail stock construction embodying an improved nonrotating, axially reciprocable quill having an axial bore therethrough in which the tail stock spindle is rotatably mounted. One of the prime objects of the invention is the provision of radial and thrust bearings which are 3,198,042 Patented Aug. 3, 1965 lCe thrust load and very little, if any, radial load; and wherein a minimum of bending movement is or will be imparted to the spindle in the event that some radial load is applied thereto.

A further prime object of the present invention is the provision of radial and thrust bearings which are positioned such that the quill will take all of the radial load and bending moment as the result thereof, but no thrust load.

Another object of the invention is to provide a quillspindle construction having the hereinabove described characteristics wherein the thrust on the spindle is transmitted directly to a thrust plate which is secured to and carried by the rear end of the spindle and wherein the forces which advance, retract and/or maintain the quillspindle combination relative to the tail stock frame are applied directly to and'axially of said thrust plate from a location beyond the rear end of the spindle and quill.

Still another object of the invention is to provide a tail stock assembly with improved lubrication of the spindle and quill bearings, and additionally the provision of an improved removable center point structure and mounting including spindle engaging and intertitting parts and means for ready disassembly or removal of the center from its supporting spindle.

A further object of the invention is the provision of a novel improved hydraulic operating, controlling, and lubricating system for a tail stock assembly as aforesaid, which includes independent circuitry for power control of positioning of the work engaging center and for operation of the safety mechanism, and an additional circuitry for insuring and effecting adequate lubrication of the several slide bearing surfaces and anti-friction bearings of the tail stock assembly.

These and other object-s are attained by the means described herein and as disclosed in the accompanying drawings, in which:

FIG. 1 is a side elevation of a tail stock assembly or structure embodying the teachings of the present invention with parts thereof broken away and inner structure elements shown in section.

FIG. 2 is an enlarged partially sectional view illustrating details of the forward portion or left end of the assembly of FIG. 1.

FIG. 3 is an enlarged, partially sectionall view of the central portion of the assembly of FIG. 1, particularly illustrating the thrust and radial bearing mounting of the rear end of the spindle and quill.

FIG. 4 is an enlarged elevation of the rear or right end portion of the assembly of FIG. 1, with the automatic safety control adjusting mechanism shown in section.

FIG. 5 is an end or rear elevation of the right end of the assembly of FIG. l. ln each of FIGS. l and 4 those portions to the right of the reference line X-X have, for clarity of detail and understanding, been rotated in a counterclockwise direction from the true position of said parts as illustrated in FIG. 5.

FIG. 6 is a schematic diagram of the hydraulic actuating and lubricating circuits of the assembly of FIG. l.

With reference to the drawings, the numeral 10 denotes generally a tail stock assembly embodying the teachings of the present invention, said assembly being mounted for longitudinal movement relative to an elongate bed 12, such as, by way of example, on ways 14 and 16 which ride upon hardened guide strips 18 and 20, respectively, which are secured to and carried by bed 12, as illustrated in FIG. 5.

The numeral 22 denotes a nut bracket which is iixed relative to the movable tail stock assembly for cooperation with suitable means, not illustrated, by which the entire tail stock assembly may be moved relative to the bed.

ry The present invention .is neitherA concerned 'with rior annessa directed to the particular means by which a utail-stoele- .4f The numeral 138 denotes a Vthrust washer disposed between thenut and inner race. a

.The letter J denotes an O-ring, or other suitable seal- 1 ing member, interposed between the adjacent portions of thrust plate 106, quill 619 and bearing spacer 163 for providing a fluid tight joint, for reasonshereinafter more .44 will urge the aforesaid inclined surfaces ofthe clamp 34 and` 36 forsecurely though releasably locking the ytail v stock assembly to the bed;

With particular reference now to FIG. 1, the numeral 50' denotes a spindle which is rotatably. journaled kwithin f an elongate quill 60-which is rectangular in transverse section, note FIG. 5, and which is mounted for longitudinal movement relative to the tail stock structure on lgibs 62 and 64 securedto and carried by side plate 66 and element 68 of the tailstock structure,irespectively. The kupper surface A of the quill is provided with an elongate members into tight, contacting relationship withl surfaces fully apparent. f Y

With reference now tol-FIG. 2, it Vwill be noted that the forward end of the quill isi-recessed as at for receivi 4ing the outer race 152k of a pair of radial bearings 154 and 156. The inner races'158a-nd 16@ are received on cylindrical portion 162 ofthe spindle which defines an axial face 164 which is engageable by the rear face of race 160. Y

VThe foifwardface of race`158 is engaged .bythe axial .fa-ce 166 of peripheralport'ion K Vofa removable center Adenoted generally by the letter M.

Y The outer race 15,2 .is unrestrained, that VVis, it is not confined aga-inst axial, endwise movement relative to the quill within recess 150; therefore, no thrust load is im- VVparted to the quill `which will take onlyjradical loads and V or groove 63 having an inclined surface 65 which conof gib 64. The rear surface B of the quill is'provided with an elongate V or groove 163 having'an inclined surface 16S which contacts and slidably engagessurface 161 ofthe Ytacts and slidably` engages surface 61'of the guiderib 59V guide rib 159 of gib 62. In this manner lower face`17lV and frontface '72 of the quill are disposed and maintained in slidable, contacting relationship with bearing surfaces 74 and 76 of the tail stock structure, respectively. VFaces A and B are free yof contact with adjacent .portionsof the tail stock frame, viz., upper plate 67 and side plate` 66, asV illustrated.

With further reference vto FIG.'1, it will be noted that the quill is axially bored to receive the spindleV andthe various bearing assemblies by which the spindle is rotati ably mounted in the quill. Y.

Endwise axial movement of the quill relative to the tail stock structure is accomplishedby means of Va hydraulic l rods and 9272 which are suitably secured to Land carried by piston 94.l Piston rod 90 projects through aperture 96 vof rear plate .86 and terminates in a forward end which threadably engages thrust plate or abutment Vend plate 160 at 1702.? A

thrust washer'98 may vbe interposed lbetween adjacent faces Y' of rod 90 and plate 100, as illustrated in FIGS. land vIt.

Thrust 'plate 100 is rigidly secured to the rear end-194V of quill l60 by bolts 106; and' a y.bearing spacer .ringer Vvcollar 108 having a forward axial face V109 is anchored Vto the thrust plate by bolts 110.

With particular reference now to FIG,Y 3, it will be noted that the rear portion of spindle ,50 is provided-'with an annular portion ,112 having a rear axial lface 114;'a'cylindrical portion C ofr reduced diameter having a-rear axial face 116;'and a reduced terminalportion D,'the endl ofwhich is externally threaded as at 11,8. Y' .I

VA thrust lbearing 120'is disposed betweenraces 1122' and 124 whose respective axial faces engage axia'l'faces 11,4 and y1(19 of the spindle and bearing spacerV ring 19S, respectively. p Y f In theV preferred embodiment of the inventioina radialA or stabilizer bearing is disposed between the V'terrni- 1 nal portion Def the spindle and the'bearing spacer ring' 108, wherein the youter raceABZ-engagesthe beaniniglr. spacer and the inner race 134 is carried on .portion Der the spindle' to which it is' secured( with Aits forward 'end abutting'axial face 116 of the spindle by reason of nut 136 engaging the threaded portionlltlV ofV the spindle. j75l bendingmovement.

Fromthe foregoing,` it will be noted that thev spindle will take allof thethrustloa'd and very-little, if any,

' v radial load; but in' any event, the spindle will never be subjected tomore than Vayminirnum bending moment as thel result of a radial load applied thereto. Y

With further reference to FIG. 2, it will be noted that the forward end of the spindle issuitalbly recessed toy receive the annular concentriqforwardly 'projecting por- Y' tions 182:and 194of centervM,V and to provide an interference lit Vtherewith 'as ,at Y136. The center M may be Vsecurely thouglireleasably anchored to the forward end sageways whichextend between a (closedv chamber P defined by the adjacent surfaces of the spindle and center to the right of the interference tat V1556. A grease fitting Ztl@ which isaccessiblefromthe exterior of conical face 1202 of the center vM is disposed for communication with passageway 192, as illustrated. The introduction of iluid vunder piressureinto chamber P, via fitting 200, after bolts 188 have been removed, wil-lconveniently eject center M from spindle 50. i i

With further reference Vto FIG. 2, it will be noted that an'annullar seal retainer ring 151 may be secured to and carried by the Vforward ,end of the quill by bolts 153.

An O-ring 149 ,isi interposed between said ring and the quill,`r` andA aY lip seal 1551's provided in spanning relationship betfweenthe retainer ring and annular surface 157er center M `for providing an oil-tight lubricant chamber .G whichisV in open communication with chamber KY iat the rear end of the spindle and quill Via` clearance 159 i Y between the spindle andquill.

.The numeral 161 denotes an oil return line which is provided in ,andt extends throughthe quill and which i is in open communicationwith chamberG via passageway 163. .Return line 161V is suitably connected to a sump S, seeFIG. 6, by suitable piping suchY as 165.

l QUILL STOP With :reference now to FIG.' 4, it will be noted that the major portion of pis-ton rod-92 is axially bored as at 208 and internally threaded` toreceive andengage the externalthreads fof a lead screw212 formed integral with .inner shaft'element 214, gear 216,. and outer` shaft element 218, which latter element terminates in an out- Ywardly:projecting stem 220 o f reduced diameter. having a VVVsuitable indent-ation in the vfree outer end thereof for ypartially. receiving and centering a ball `22,2 interposed between thefend of stem 220an`d the end of the axially shiftable actuator sha-ft224 of a conventional hydraulic servo-valve indicated generally by the lette-r V, which is secured to and carried by plate 248 by bolts 249 which valve.' j

` Y extend through the mounting bracket.. 251 of the 'servoe said bushings.

Inner shaft element 214 is journaled for rotation in a bushing 230 secured to and carried by the quill stop case 240, as illustrated, wherein the gear-adjacent end of the bushing is provided with an outturned peripheral bearing 'lip 232 having an axial fa enga-geable by the laxial face 234 of the hub of the gear 216.

Outer shaft element 218 is journaled for rotation in bushing 242 which includes an outturned peripheral bearing lip 244 of substantial proportions having an axial face engageable by the axial face 246 of the other hub of gear 216. Bushing 242 is secured to and carried by rear lor cover plate 248 which is securely and rigidly, t-hough releasably, anchored in position by means of tie rods 25@ and 252. Those ends of the rods remote from nuts 252 threadably engage mounting plate 82 of the cylinder assembly.

The axial faces 234 and 246 of the hub of gear 226 are normally spaced from and out of contact with the adjacent faces of bushings 230 and 242, thereby permitting limited endwise, axial movement of the gear relative to Any endwise or axial movement of the gear will, of course, be transmitted to actuator shaft 224 of the hydraulic servo-valve V via stem 224i and ball 222 for controlling both the speed and direction of rotation of hydraulic motor H.

Motor H includes ashaft 260 to which a gear 262 is ysuitably secured for driving engagement with an idler gear 264 which is keyed to or integral with shaft 266 suitably journaled for rotation relative to the quill stop case 240 and plate 248 as by bearings 263 and 27d. The free end of shaft 266 projects outwardly beyond the rear face of plate 248 and is provided with flats, or the like, ldenoted by the numeral 272 to accommodate a hand crank.

The numeral 280 denotes a suitable oil seal surrounding shaft 266; and the numerals 222, 2S4, 236 and 235, of FIG. 4, denote sealing members, such as O-rings, and thenumerals 299 a sealing element or gasket for providing an oil tight housing for the quill stop case.

An oil intake or inlet to chamber L is indicated at 291, whereas the numeral 292 denotes an oil passageway which extends throughout the entire length of piston rods 9d and 92, and through piston 94. A radial bore 294 places passageway 292 in open communication with the interior of chamber L.

From the foregoing, it will be noted that rotation ofi gear, 216 will cause lead screw 212 to be fed into or out of piston rod 92, and the purpose of the hydraulic ,servo-valve mechanism V is to correlate the speed and direction of rotation of lead screw 2l?. with the dire- ,ti-on and rate of axial movement of piston rod 92 incident to actuation of piston 94 of the hydraulic cylinder titi, so that gear 2l6 will remain in spaced relationship with the axial faces of bushings 23@ and 242.

If the rate of linear travel `of the piston to the left (of FIG. 4) should exceed the rate at which lead screw 2l?. is being retracted from piston rod 92, the lead screw, gear 26, and stem 22@ will be shifted to the left for thereby actuating valve V to increase the speed of motor H for increasing the rate of rotation of the lead screw Lto compensate for the rate of travel of the piston. Quite obviously, if the rate lof rotation of the lead screw is not speeded up, face 234 of the hub of gear 2l6 will be lshifted to the left into interfering relationship with the axial face of lip 232 of bushing 236i.

By the same token, movement of the piston to the right (FlG. 4) will tend to shift the lead screw 212, gear 2te, and stem 22d to the right for actuating shaft 224 of valve V to drive motor H at such a rate and in such a direction as to rotate the lead screw into threaded engagement` with piston rod 92 for fully compensating for the axial movement of the piston, whereby gear 2id will be maintained in spaced relationship with respect to the axial `faces of the bearing lips of bushings 23d and 242.

The primary purpose of the quill stop mechanism is to provide efficient, positive means which will positively preclude accidental and/ or unintentional retraction of the spindle and quill in the event of hydraulic failure, which failure would, or could, but for the quill stop aforesaid, result in the quill being retracted and the center M withdrawn from the workpiece with disastrous results.

The aforesaid quill stop will positively prevent unintentional or accidental retraction of the quill by an amount greater than the normal spacing of an eighth of an inch or less between surface 246 of the hub of gear 216 and the adjacent axial face of lip 244 of bushing 242, in the event of hydraulic failure.

Since, in the event of hydraulic failure, relative motion between the screw and piston rod 92 will be prevented whereby retraction of the quill and spindle will cause surface of bushing 242 for transmitting the axial or thrust loa-d of the spindle to rear plate 24S, nuts 252, tie rods 25d, mounting plate 82, and bolts $4 back to the rear plate 36 of the tailstock structure.

HYDRAULIC SYSTEM With particular reference now to FIG. 6, the numerals Bild and 3532 denote a pair of commercial pressure-compensated pumps suitably driven by a motor 304. The characteristics of pump 36d are such as to provide and maintain a constant pressure within line 306 which is connected to the inlet port 3% of the hydraulic servovalve mechanism indicated generally by the letter V. Outlet port Slt? and valve V is suitably connected by means of conduits Sid and 326 to one side of reversible hydraulic motor H; and outlet port 312 is suitably connected by conduit 3318 to the other side of said motor. A manually controlled valve 32) is interposed between conduits 324 and fait? as illustrated for a reason which will hereinafter be more fully explained.

The present invention is neither directed to nor concerned with the particular structural details of the servo valve V, it being understood that said valve is adapted to cause motor H to rotate in one direction for rotating and withdrawing lead screw 212 from piston rod 92 incident to movement of said rod to the left (as viewed in FIG. 6); and to rotate motor H in the opposite direction for advancing the lead screw into piston rod 92 incident to movement of said rod to the right (as viewed in FIG. 6).

.Pump 392 is adapted to provide lubricating oil under pressure through conduit 320 to conduits 322, 324 and 326, wherein conduit 322 is in open communication with passageway Zell of chamber L (see FG. 4) of the quill stop mechanism. The lubricating oil thus pumped into chamber L will completely lubricate all of the moving parts of FlG. 4 and also pass forwardly between the quill and spindle via opening 159 (FIG. 2), thence forwardly to cham er G, thence through passageways 163 and llll (of FG. 2) through conduit 165 (FIG. 6), into a common sump S.

The fluid under pressure in conduit 320 is also utilized for actuating piston 94 of cylinder 8l) for advancing, holding and/ or retracting the quill and spindle assembly relative to the tailstock structure. A manually operable directional four-way valve denoted generally by the numeral 33d may be utilized for interrupting the flow of fluid under pressure to cylinder Si?, or for selectively providing fluid under pressure to on-e or the other sides of piston 94.

The piston will be advanced incident to movement of valving member 33d to the right whereby passageway 332 will connect conduit 324 in open communication with conduit 334, through check valve 336 and conduit 338 to the right end of cylinder 30, in which event the left end of said cylinder will be exhausted through conduit 34d which will be placed in open communication by means of passageway 342 of valve 336 in open communication with conduits 344 and 346, wherein conduit relief valve 34S.

, fr Y 344-'is connected to common sump S through a suitable The numeral 36o-indicates ,generally a pilot operated check valve, the pilot being indicated atltl on V5143.116. Check valve 336 is closed only when the pressure on pilot operating device 33? fails to provide` suflicientrpres-V Y 'Y sure from pump 3%2 to open it. The pilot operatedVV valve 336 ispmerely a safety device which in the case of loss of pressure for any reason will positively preclude therretraction of pistonr94,-which retraction'wuld allow the workpieceV to drop out from between centers.

The numeral 343 denotes a relief valve in the exhaust lines 344 and 34o of the system for the purpose of maintaining pressure in the system above the pressure-setting for pressure switchZ so that center M and piston 94 can Vbe moved back and forth without restriction of the work- Y l. Aroll lathe tail fstockY including a frameV piece engaging them vto maintain pressure in the system.VY

The fluid passing through conduit'fie will be fed through bleeders or BUUR ttings F into lubrication` lines 35%,.

352, 354, 356,' 35S, 369, 362`and 364, which are in open communication with suitable conduits, not illustrated, which supply lubricant to the adjacent contacting surfaces Til-74 `and 72-76 Vof .the quill and 'quill support,

and to the V-way slide bearings at surfaces 61435V and 161-165 as illustrated in FlG.V 5.

At this point it should be'noted'that piston 94 will be shiftedto the left 'for` causing center Mto engage Vand then exert sufhcient axial .thrust to one YendV of/a roll for mounting said roll for rotation between` theY i headstock andA a tailstock assembly,Y not illustrated..y In f order to insure proper and continuous seating of center M with the tailstock Vend of a roll, hydraulic `pressure will be continuously maintained on the right said Vof piston 94. In this'rnanner Vany expansion or contraction of the workpiece resulting in axial elongationror shortening thereof will be automatically and continuously compensated forby reason of such axial movement being transmitted'directly to the piston which'will be automatically retracted or'advancedto maintain Va constant axial force to the workpiece via centery M,. by reason i of the setting of pressure compensated ypump3&2. Vto automatically accommodateVand'compensate for elongation Aor shortening of the workpiece Vby Vchanging'the vand those structural elements which" are for permitting th'efree, unrestricted passage of iluid through or relative to-motor H and cylinder 80.

lVlanualV operation Aof Vgear 264=will cause lead screw` `212 to be rotated relative to "piston rod 92 for intially shifting gear 215 until'an axial force'of its hub engages Vand abuts against a correspondingaxial face of the bearving lip of an fadjac'ent'bushing 230 or 242; thereafter Vfurther rotation Vvof* the lead screw inthe same direction will impart. endwise axial movementto piston rodv92,

i directly or indirectly secured thereto.

What isclaimed is: i having interior angularly related'slide bearing faces, a hollow quill mounted in the frame having angula-rly related ex- :terior bearingfaces' interitting with the slide faces'of the fra-me and guided thereby, al live ytail center spindle vmounted in said hollow quill having a terminal'cone spacing ring forming a' closure for the rear end of said 4 chamber'and an ,abutment stop for the end-thrust bearing, a thrust Yplate secured to the .rear face of the quill,

Vretaining the spacing ring in (position, in the `chamberof the quill to transferthe end thrust on the cone and its spindlerdirectly to said thrust vvplate, a radial-thrust antifriction. bearing intervening the `rear end of the spindle and said yspacing ring, and power operated means connectedtosaid thrust plate for axially. moving the quill and spindle, and receiving.thrustdirectlyfrom the load on the spindle.

, 2. -A machine tool tail stock including a Vframe having interior'angularly related slide bearing faces, a hollow quillk mounted in the vframe having angularly related exterior bearing faces intertting with the slide faces i of the frame and guided thereby, av livejtail center spindle volumetric displacement to provide constant pressure toV Vthe system even though the volumetric demand of the system may fluctuate.' y v n Y Y The letter Z denotes apressure switch which is adapted to automatically stop the machine and prevent it from being operated during those periods 'of time when the 'Y pressure in line 32@ falls below a certain predetermined or pre-set value. Y n

Th enumeral 321 denotes a manually operable valve which is normally closed.

If the hydraulic system should fail,fspin`dle canY only retract a fraction of an inch to the right, as determinedby contact of face 246 of the hub of gear216- with the axial surface of bearing lip 244 of the busliing.k

242, as already set forth.

The spindle may be retracted by'n'ianipulating valve Y 3063 for placing passageway E'tl'thereof in vopen communication'between conduits 324 and ,34d and for'placing passageway 372 in open communication .with-conduits 334 and 346. During such retraction of piston94 check valve 336 will be opened for permitting flowof oil from conduit 338 into vlysaidcheck valve Ybeing vopen by reason of the application of Aline Ypressure,

through conduit V326 `which. actuates theV pilot actuated check valve denoted generally by the numeral 380. As

before, the fluid `in conduit'34v6 will be Vfedto conduits 35@ through 364 inclusive for lubricatingthe'quill. When Ythe machine isshut downthe quill and spindle assembly may be .advanced or; retracted-.manually bynVV rotating gear 264 byrawrench, crank or handwheelapplied to the. squared en d 272, vof shaft 266;`after,however,

both of valves 320 and il'have been manually' opened mounted in saidhollow quillv havingy a terminal cone center, said quill having a radial bearing, receiving recess y formed in its forward 'end and abearing receiving chamber formed inits rear end, aradial bearing mounted on the forward end of the yspindle adjacent the center, said bearing having an outer race slidably mounted in the recess ofthe quill, an end-thrustbeang mounted o n the rear. portion of the spindleV and disposed within the cham- `ber of the quill, la spacingY collar forming a closure for the rear end of the chamber and an Yabutment stop for the end-thrust bearing, an abutment endfplate secured to the rear face of the .quill retainingthe collar in position the chamberfofthe'rquill to'transfer the end-thrust on the coneand its spindle directly to said 'end plate, and a radial-thrust bearing intervening the rear end of the spindle and the collar, a hydraulic quill-operating motor including a cylinder secured to the frame, apiston slidable in the cylinder and a forwardly extending piston rod connectingthe piston Vand end plate for'eiecting fendwise 1 reciprocation ofthe quill and spindle Y with movements of the` piston.

3. ,A machine tool tailgstock including a frame having v in correspondence interior angularly. relatedslide bearing faces, a lhollow quillV mounted in the frame having angularly related exterior bearing faces. interfitting with the slide faces of the 'frame and guided thereby, a live tail center spindle mounted insaid hollow quill'. having ar terminal cone i center,-said Yquill havinga'radial bearing receiving recess Y' formedin its forward end and a bearing receiving chamberformed ingits-rear end,.a,radia1bearing mounted on rthe .forward end i* ,oftheY spindle adjacentlthe center, said bearing`having ank outer race'slidably mounted., in the recessof the. quill, an end-thrust bearing `mounted on the rear portion of the spindle and disposed within the chamber of the quill, a spacing collar forming a closure for the rear end of the chamber and an abutment stop for the thrust-bearing, an abutment end plate secured to the rear face of the quill retaining the collar in position in the chamber of the quill to transfer the end-thrust on the cone and its spindle directly to the abutment end plate, a radial-thrust bearing intervening the rear end of the spindle and the collar, a hydraulic quill operating motor including a cylinder secured to the frame, a piston slidable in the cylinder and a forwardly extending piston rod connecting the piston and abutment end plate for effecting endwise reciprocation of the quill spindle in correspondence with movements of the piston, a second piston rod extending rearwardly from the piston, and a fmechanical thrust-take-up-mechanism coupled to and reacting on the said second piston rod to limit movement of the piston and coupled quill and spindle.

4. A machine tool tail stock including a frame having interior angularly related slide bearing faces, a hollow quill mounted in the frame having angularly related exterior bearing faces intertting with the slide faces of the frame and guided thereby, a live tail center spindle mounted in said hollow quill having a terminal cone center, said quill having a radial bearing receiving recess formed in its forward end and a bearing receiving chamber formed in its rear end, a radial bearing mounted on the forward end of the spindle adjacent the center, said bearing having an outer race slidably mounted in the recess of the quill, an end-thrust bearing mounted on the rear portion of the spindle and disposed within the chamber of the quill, a spacing collar forming a closure for the rear end of the chamber and an abutment stop for the end-thrust bearing, an abutment end plate secured to the rear face of the quill retaining the collar in position in the chamber of the quill to transfer the end-thrust on the cone and its spindle directly to said end plate, a radialthrust bearing intervening the rear end of the spindle and the collar, a hydraulic quill operating motor including a cylinder secured to the frame, a piston slidable in the cylinder and a forwardly extending piston rod connecting the piston and abutment end plate for effecting reciprocation of the quill and spindle in -correspondence with movements of the piston, and a mechanical thrust takeup coupled to and reacting on the piston to limit its reciprocating movement, said mechanism including a lead screw, an actuating motor for the lead screw, and an endthrust-actuatable servo for -controlling the operation of the lead screw actuating motor.

5. A tail stock for a heavy duty roll lathe, including a frame, a quill mounted in the frame for longitudinal sliding movement, means restraining the quill against rotation, a live tail center spindle rotatably supported by the quill, a reciprocating hydraulic motor including a piston and cylinder carried by the frame, means coupling the piston to the quill for effecting power positioning of the quill relative to the frame, and an auxiliary mechanical control for the position of the piston and quill relative to the frame including a lead screw coupled to the piston for bodily movement therewith and relative thereto, abutment means for limiting the joint bodily movement of the piston and screw in either of two opposite axial directions, and driving mean-s for effecting rotation of the screw in opposite directions to increase or decrease the effective overall length of the combined coupled quill, piston and screw to effect positioning of the quill.

6. The construction as specied in claim S, in which the driving means includes a manually operable member for effecting rotation of the screw to effect positioning of the quill.

7. The construction as specified in claim 5, in which the driving means for effecting rotation of the screw includes a motor and a servo control connected to the motor, cooperating with the screw, and actuatable by axial movements of the screw to control the operation of the motor.

8. A tail stock unit for a machine tool, including a frame having rectangularly related portions providing a wide horizontal basal slide surface and a wide vertical slide surface at one side of and perpendicular to said basal surface, a quill slidably mounted in the frame having corresponding basal and side slide surfaces for inter-engagement with the said surfaces of the frame, the quill having a longitudinally extending V-way guide groove formed in its opposite side surface and in a top surface and guide blocks secured to the frame portions having V-guides for engagement in the grooves of the quill, whereby said guides and grooves secure the quill for longitudinal sliding movement while preventing twisting or binding thereof as respects the slide surfaces.

9. In combination, a tail stock structure for a machine tool, including a frame having rectangularly related portions providing basal and lateral slide surfaces, a quill slidably mounted in the frame having corresponding slide surfaces for inter-engagement with the surfaces of the frame, the quill having longitudinally extending V-way guide grooves formed in its slide surfaces and guide blocks secured to the frame portions having V-guides for engagement in the grooves of the quill, whereby said guides and grooves support the quill for longitudinal sliding movement while preventing twisting or binding thereof as respects the slide surfaces, said quill being interiorly channeled to provide a lubricant passageway, and being formed with an axially extending spindle-receiving bore, a live tail center spindle rotatably mounted in said bore, anti-friction bearings supporting the spindle within said bore and spaced from the surface thereof, a hydraulic actuating motor for actuation of the quill having a hollow piston rod coupled to the quill and communicating with said bore and said bore communicating at its forward end with said passageway, and a pressure lubrication system including a sump, a motor actuating pressure pump drawing oil from the sump, means including a motor actuating pressure conduit for connecting the pump to the motor, a distribution conduit from the pressure conduit coupled to discharge lubricant through the piston rod to the bore of the quill and by way of the bearings to the lubricant passageway and thence to the sump, and another distribution conduit from the pressure conduit coupled to discharge lubricant to the outer slide faces of the quill, and conduit means for returning the lubricant to the sump.

1t). ln combination, a tail stock structure for a machine tool, including a frame having rectangularly related portions providing basal and lateral slide surfaces, a quill slidably mounted in the frame having corresponding slide surfaces for inter-engagement with the surfaces of the frame, the quill having longitudinally extending V-way guide grooves formed in its slide surfaces and guide blocks secured to the frame portions having V-guides for engagement in the grooves of the quill, whereby said guides and groove support the quill for longitudinal sliding movement while preventing twisting or binding thereof as respects the slide surfaces, said quill being formed with an axially extending spindle receiving bore, a live tail center spindle rotatably mounted in said bore, anti-friction bearings supporting the spindle at both ends within and spaced throughout its length from the surface of said bore, a hydraulic actuating motor for actuation of the quill having a hollow piston rod coupled to the quill and communicating with the bore, means including the space between the spindle and the surface of the bore for conducting lubricant to the said bearings, and a pressure lubrication system including a sump, a motor actuating pressure pump drawing oil from the sump, means including a motor actuating pressure conduit for connecting the pump to the motor, a distribution conduit from the pressure conduit coupled to discharge lubricant through the piston rod into the bore of the quill, the frame having oil passages formed therein for discharge of lubricant at the slide surfaces, and conduits connecting the motor and passages for discharge of lubricant to the'slide surfaces by way ofl theconduits and pasn sages. v t 1l. The construction as speciiied in claim itl, in which a rst means is provided to determine the maximum pressure available :for distribution throughr'the conduits and additionalmeans arey provided for independent controlof.`

the flow of lubricant to individual passages.

operatively associated with and .actuatable by movementof the screw, a'pair of motor conduitsvcoupled to opposite t ends of the Vquill operating motor, a reversing valve inter- .CII

' 12; In a machine tool tail stock mechanism,'a tail'stock,

a piston-reciprocated work-engageable' center, a safety locking device for the piston-reciprocated.work-engageable center, said mechanism including an axially extending Vlead screw having threaded engagement with the piston,V

means on the tail stock restraining the lead `screwfto limited bodily axial movement relative to the tail stock,

13. ln a machine tool tailstock mechanism, a tail stock,

a piston-reciprocated work-engageable center, a safety locking device for the piston-ieciprocated woi'lc-engageable Y center, said mechanism including an Vaxially extending lead screw having threaded engagement with the piston, means on the tail stock restraining the lead screw to limited bodily axial movement relative/to the tail stock, power operable means for effectiuga compensating rotationof the lead screw torpermit unrestrained axial movement of the piston, movement ofthe pistonV fromV onel direction to another tending to effect a simultaneous bodily axial movement of the lead screwV therewith, a servo-control for the power operable means having a follow-up member engaging the screw and actuableupcn axial movement of the v screw to energize the power operable means, an activatable source of power, and means to de-activate the source to de-Venergize said means and prevent rotation ofthelead screw. i f l 14. In a machine tool, a tail stock, a tail stock reciprovcnirig the pressuieconduit and the pair of motor conduits yand actuatable to connect the pressure conduit to one or the other of said motor conduits to determine the direction of actuation of the motor,l a discharge conduit leadingfrom thevalve, and means for controlling thepressure in the discharge conduit.V Y f VY15. In a machine tool, a tail stock, a tail stock reciprocating quill having a work kengaging center, a hydraulic system for, control of the tail stock reciprocating quill, said Vsystem including Ya double end hydraulically operable motor for-.movement 'of the'quill, a mechanical safety device for control of the quill, including a screw coupled for movement with and rotation relative to the quill, a second motor for Vrotation ot the screw, a servo-con- -trol for the second motor, said system including a pair of pressure producing pump'sfa motor for operation of the pumps, a'pressure switch effective to stop the motor and pumps upon a drop in the pump effected pressure, a` first power circuit activated by one-of the pumps having a pres- Y sure conduit coupledto energize the switch and the quill motor, a second circuit for thesecond motor energized by the second-pump, a servo-contrpl for the second motor operativelyassociated with and actuatabletby axial movement. ofthe sci-ewwith the quill,ra pair of motor conduits coupled to opposite ends of the quill operating motor, a reversing valve intervening the pressure conduit and the pairo'motor conduits and actuatable to connect'the presf sure conduit to` one or the other or"y said motor conduits to determine the direction of actuation of the motor, a disv charge conduit leading from the valve, 'means forcontrolling the pressureV in the discharge conduit,"a branch lubricating conduit coupledrto the discharge conduit, and

` lubricant distributing conduits extending from said branch eating quill having a work engaging center, a hydraulicV Y system for control ofthe tail-stock-reciprocating-quill, said system including a 'double end'hydraulically operable motor for movement of thequill; a mechanical` safety f device for control of the quill, including a screw coupled forY movement with andv rotation relative to the quill, af second motor for rotation ofthe screw, and a servo-control Vfor the second motor, said system including a pair of pres- Y sure producing pumps, amotorv for operation ofthe pumps, a pressure switchefective to` stop the motor and i pumps Vupon a drop inl-the pump eiiected pressure, arrst power circuit activated by one of the pumps having a pressure conduit coupled to energize the switchand the` quill motor, a second circuit for the second motor energized by the second pump, and a servo-control for the secondrr'iotor operatively associated with and actuatable by axial movement of the screw. Y. Y

l5. In a machine tool, atail stocl ,'a'tail stock reciprocating quill having a workrengagingcentcr, a hydraulic sys-V tcm for control of the taily stock reciprocating quill, said system includinga double end hydraulically operable'ino- ,Y f

tor for movement ofthe quill, a mechanical safety device for Vcontrolof theV quill, including a screw, ,Coupled for movementiwith and rotation relative to the quill, a second motorr for rotation of the screw, a servo control for the secondrmotor, said hydraulic system including4 a pair of pressure producing pumps, a motor Vfor operationVV of the pumps, al pressure Vswitch efective'to stop the motorand Y sure conduit coupled to energize Vthe switch and the quill l motor, a second circuit toi' second motor'energized by .Y the second pump, a servo controlltor theY second motor.VY

i conduit to slide'bearing surfaces in thetail stock.

Y Y 17. InaV machine tool, atail stock, a tail stock reciproeating quill having a work engaging center, a vhydraulic system for control of the tail stockreciprocating quill, said system includingy a double end hydraulically operable motor ifor movement.v of the quill, av mechanical safety device for control of the quill, including a screwy coupled formoveinent with and rotation relative toy the quill, a secondmotor forV operation of the screw, av servo-'control for the lsecond motor, said system including a pair of pressure producing pumps, a motor for Yoperation Vof the pumps, a pressureswitch eifectiveftofstop the `motor and pumps upon a Ydrop inthe pump effected pressure, a first V`power circuit activated byone of the pumps having a presoperatively associated with and actuatable by movement of` thescrew with the quill, -a pair vof motor conduits coupled i lto opposite ends of the quill operating motor, a reversing valve intervening the pressure conduit and a pair of motor conduits and actuatable to connect theV pressure conduit toV one or the other of said motor conduits to determine the direction of actuation of the motor,a check valve vin one of,Y theV pair V'ofl motor conduits intermediate the reversing valve and the Ymotor eiective when'closed to block return flowl from the motor and iinpound impelling VVfluid then present in the motor, and pressure actuatable i means operatively connected to the pressure conduitinter.-

mediate the pressure pump and the reversing valve, operative by pressure in the conduitto hold the check valve in open, non-blocking position.

V 18; A machine tool tail stock, including ra, work engaging center, areciprocable mounting for the center including a spindle, a'reciprocatiiigrhydraulic motor for moving and `yieldably holding the spindle andcenter in Work clamping stock for rotation and for restricted axial movement, a threaded connection between the lead screw and the motor, whereby the limited axial movement of the lead screw provides a variable restriction for movement of the center, a servo-controlled motor for rotation of the lead screw, and a servo-valve for control of the motor operatively associated with the lead screw and actuatable by axial movementof the lead screw to actuate the servomotor for compensatory rotative adjustment of the lead screw.

19. In a machine tool tailstock assembly, a rotatable center-supporting spindle having a concentric socket formed in an end thereof, a work-positioning center having a peripheral attaching flange, a centering cone projecting at one side of the flange and a cylindrical centering portion projecting oppositely therefrom concentrically fitted into the socket of the spindle, the body of said center having a conduit passage extending from the surface of the cone through the cylindrical portion to the surface of the base thereof, whereby a pressure media may be introduced through said pasage to the socket to facilitate removal of the center from the spindle, and removable securing means fastening the flange to the spindle end outwardly of the socket thereof.

20. A roll lathe tailstock including an elongate frame having interior angularly related slide bearing faces, an elongate, hollow quill mounted in the frame having angu larly related exterior bearing faces interlitting with the slide faces of the frame and guided thereby, a live tail center spindle mounted in said hollov,I quill, means at both ends of the spindle rotatably mounting the spindle to the quill, said means supporting the spindle to take all of the thrust load and relatively little bending moment and whereby the quill will take radial load and bending moment but none of the thrust of a load applied to the spindle.

References Cited by the Examiner UNITED STATES PATENTS 1,821,331 9/31 Svenson 82-31 1,891,220 12/32 Bath 82-31 X 1,921,502 8/33 Brill 82-31 2,042,123 5/36 Pierle 82-31 X 2,326,106 8/ 43 Van Ness et al.

2,493,475 1/50 Casella et al. 82--31 2,5 86,127 2/52 Von Zelewsky 82--31 2,614,447 10/ 62 Lomazzo 82-31 WILLIAM W. DYl-ER, JR., Primary Examiner. 

5. A TAIL STOCK FOR A HEAVY DUTY ROLL LATHE, INCLUDING A FRAME, A QUILL MOUNTED IN THE FRAME FOR LONGITUDINAL SLIDING MOVEMENT, MEANS RESTRAINING THE QUILL AGAINST ROTATION, A LIVE TAIL CENTER SPINDLE ROTATABLY SUPPORTED BY THE QUILL, A RECIPROCATING HYDRAULIC MOTOR INCLUDING A PISTON AND A CYLINDER CARRIED BY THE FRAME, MEANS COUPLING THE PISTON TO THE QUILL FOR EFFECTING POWER POSITIONING OF THE QUILL RELATIVE TO THE FRAME, AND AN AXIALIARY MECHANICAL CONTROL FOR THE POSITION OF THE PISTON AND QUILL RELATIVE TO THE FRAME INCLUDING A LEAD SCREW COUPLED TO THE PISTON FOR BODILY MOVEMENT THEREWITH AND RELATIVE THERETO, ABUTMENT MEANS FOR LIMITING THE JOINT BODILY MOVEMENT OF THE 